# python和java中的变量本质不一样，python的变量实质上是一个指针 int,str 便利贴

a = 1
a = "abc"
# 1.a贴在1上面
# 2.先生成对象 然后贴便利贴

a = [1,2,3]
b = a
b.append(4)
print(a)
print(id(a), id(b))
print(a is b)

a = [1,2,3,4]
b = [1,2,3,4]
a = 1
b = 1
a = "abc"
b = "abc"

print(id(a), id(b))
print(a is b)

class People:
    pass
person = People()
if type(person) is People:
    print("yes")
if isinstance(person, People):
    print("yes")







